On Wed, Jul 13, 2016 at 07:21:09AM +0200, Rafał Miłecki wrote: > On 13 July 2016 at 06:51, Peter Chen <hzpeterchen@xxxxxxxxx> wrote: > > On Tue, Jul 12, 2016 at 02:35:18PM +0200, Rafał Miłecki wrote: > >> I was working on an "usbport" LED trigger driver and specifying its > >> default state in DT. I realized I can't really determine numbering of > >> USB ports on any device as it depends on compiled drivers and the > >> loading orders. > >> > >> It means that my physical USB port can be e.g. 1-1 or 2-1 depending on > >> my current config/setup. I needed a way to specify a particular HCD in > >> DT and then hardcode port number (as this part doesn't change). > >> > > > > I have a question: > > > > What does your "usbport" LED trigger for? What kinds of information > > you would like to show on LED? > > It's a trigger that turns on LED whenever USB device appears at > specified USB port. There are plenty of home routers that have USB > labeled LED(s). To support them nicely, first of all we need a trigger > that will watch for USB subsystem events. Secondly we need a way to > setup its initial state correctly as most users don't want to play > with sysfs on their own. > > I sent usbport trigger in: > [PATCH] leds: trigger: Introduce an USB port trigger > <1468239883-22695-1-git-send-email-zajec5@xxxxxxxxx> > https://lkml.org/lkml/2016/7/11/305 > You may read commit message and ledtrig-usbport.txt for more details. > Well, it is an interesting use case. You can try to add provider (un)register at hub driver (drivers/usb/core/hub.c) instead of each platform drivers, you could refer my USB pwrseq as an example[1]. For roothub, you can get the busnum through comparing controller's of_node, for internal hub, you can get hub's dev name like (1-1) through comparing its of_node (you need to describe your hard-wired hub on dts). http://www.spinics.net/lists/linux-usb/msg143699.html Two more questions: - How to support the USB device on the port when boots up? - Any cases we need to add mapping using new_port_store, the user may not know bus number for physical port. -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
